1. Field of the Invention:
The present invention relates to a die locking mechanism and, more particularly, to a die locking mechanism for a molding apparatus having at least one movable die assembly. Such a molding apparatus may be an injection molding, compression molding or transfer molding machine having at least one stationary die assembly and at least one movable die assembly. Alternatively, a molding apparatus to which a die locking mechanism according to the present invention is to be applied may be a blow molding machine having a sectional mold consisting of two mold halves.
2. Description of the Related Art:
During operation of an injection molding machine, it is sometimes required that the machine be temporarily shut down with the movable die assembly of the machine held in a certain position with respect to the stationary die assembly. On the other hand, there is a known injection molding machine which is equipped with a safety door which, when held closed, prohibits operator access to the die blocks of the machine. In the case of an injection molding machine having such a safety door, it is desirable that the movble die assembly of the machine be held at rest in a certain position whenever access to the die assemblies is allowed to the operator of the machine with the safety door opened up either accidentally or for any purpose.
An injection molding machine having a safety door arrangement is for these reasons further equipped with a die locking mechanism which is adapted to have the movable die assembly locked under predetermined conditions of the machine such as when the safety door is held in an open position. Such a prior-art die locking mechanism however has some drawbacks in that, for example, the stop position at which the movable die assembly is to be brought to a stop by means of the locking mechanism is dictated uniquely by the geometry of the die locking mechanism. The present invention contemplates the provision of an improved die locking mechanism which will eliminate such drawbacks of a prior-art die locking mechanism for a molding apparatus, typically an injection molding machine.